/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
/*
 * Copyright 2015-2021 Amazon.com, Inc. or its affiliates. All rights reserved.
 */

#ifndef ENA_XDP_H
#define ENA_XDP_H

#include "ena_netdev.h"
#include <linux/bpf_trace.h>

/* The max MTU size is configured to be the ethernet frame size without
 * the overhead of the ethernet header, which can have a VLAN header, and
 * a frame check sequence (FCS).
 * The buffer size we share with the device is defined to be ENA_PAGE_SIZE
 */
#define ENA_XDP_MAX_MTU (ENA_PAGE_SIZE - ETH_HLEN - ETH_FCS_LEN -       \
                         VLAN_HLEN - XDP_PACKET_HEADROOM -              \
                         SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))

#define ENA_IS_XDP_INDEX(adapter, index) (((index) >= (adapter)->xdp_first_ring) && \
        ((index) < (adapter)->xdp_first_ring + (adapter)->xdp_num_queues))

enum ENA_XDP_ACTIONS {
        ENA_XDP_PASS            = 0,
        ENA_XDP_TX              = BIT(0),
        ENA_XDP_REDIRECT        = BIT(1),
        ENA_XDP_DROP            = BIT(2)
};

#define ENA_XDP_FORWARDED (ENA_XDP_TX | ENA_XDP_REDIRECT)

int ena_setup_and_create_all_xdp_queues(struct ena_adapter *adapter);
void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
                                          struct bpf_prog *prog,
                                          int first, int count);
int ena_xdp_io_poll(struct napi_struct *napi, int budget);
int ena_xdp_xmit_frame(struct ena_ring *tx_ring,
                       struct ena_adapter *adapter,
                       struct xdp_frame *xdpf,
                       int flags);
int ena_xdp_xmit(struct net_device *dev, int n,
                 struct xdp_frame **frames, u32 flags);
int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf);
int ena_xdp_register_rxq_info(struct ena_ring *rx_ring);
void ena_xdp_unregister_rxq_info(struct ena_ring *rx_ring);

enum ena_xdp_errors_t {
        ENA_XDP_ALLOWED = 0,
        ENA_XDP_CURRENT_MTU_TOO_LARGE,
        ENA_XDP_NO_ENOUGH_QUEUES,
};

static inline bool ena_xdp_present(struct ena_adapter *adapter)
{
        return !!adapter->xdp_bpf_prog;
}

static inline bool ena_xdp_present_ring(struct ena_ring *ring)
{
        return !!ring->xdp_bpf_prog;
}

static inline bool ena_xdp_legal_queue_count(struct ena_adapter *adapter,
                                             u32 queues)
{
        return 2 * queues <= adapter->max_num_io_queues;
}

static inline enum ena_xdp_errors_t ena_xdp_allowed(struct ena_adapter *adapter)
{
        enum ena_xdp_errors_t rc = ENA_XDP_ALLOWED;

        if (adapter->netdev->mtu > ENA_XDP_MAX_MTU)
                rc = ENA_XDP_CURRENT_MTU_TOO_LARGE;
        else if (!ena_xdp_legal_queue_count(adapter, adapter->num_io_queues))
                rc = ENA_XDP_NO_ENOUGH_QUEUES;

        return rc;
}

static inline int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
{
        u32 verdict = ENA_XDP_PASS;
        struct bpf_prog *xdp_prog;
        struct ena_ring *xdp_ring;
        struct xdp_frame *xdpf;
        u64 *xdp_stat;

        xdp_prog = READ_ONCE(rx_ring->xdp_bpf_prog);

        verdict = bpf_prog_run_xdp(xdp_prog, xdp);

        switch (verdict) {
        case XDP_TX:
                xdpf = xdp_convert_buff_to_frame(xdp);
                if (unlikely(!xdpf)) {
                        trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
                        xdp_stat = &rx_ring->rx_stats.xdp_aborted;
                        verdict = ENA_XDP_DROP;
                        break;
                }

                /* Find xmit queue */
                xdp_ring = rx_ring->xdp_ring;

                /* The XDP queues are shared between XDP_TX and XDP_REDIRECT */
                spin_lock(&xdp_ring->xdp_tx_lock);

                if (ena_xdp_xmit_frame(xdp_ring, rx_ring->adapter, xdpf,
                                       XDP_XMIT_FLUSH))
                        xdp_return_frame(xdpf);

                spin_unlock(&xdp_ring->xdp_tx_lock);
                xdp_stat = &rx_ring->rx_stats.xdp_tx;
                verdict = ENA_XDP_TX;
                break;
        case XDP_REDIRECT:
                if (likely(!xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog))) {
                        xdp_stat = &rx_ring->rx_stats.xdp_redirect;
                        verdict = ENA_XDP_REDIRECT;
                        break;
                }
                trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
                xdp_stat = &rx_ring->rx_stats.xdp_aborted;
                verdict = ENA_XDP_DROP;
                break;
        case XDP_ABORTED:
                trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
                xdp_stat = &rx_ring->rx_stats.xdp_aborted;
                verdict = ENA_XDP_DROP;
                break;
        case XDP_DROP:
                xdp_stat = &rx_ring->rx_stats.xdp_drop;
                verdict = ENA_XDP_DROP;
                break;
        case XDP_PASS:
                xdp_stat = &rx_ring->rx_stats.xdp_pass;
                verdict = ENA_XDP_PASS;
                break;
        default:
                bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, verdict);
                xdp_stat = &rx_ring->rx_stats.xdp_invalid;
                verdict = ENA_XDP_DROP;
        }

        ena_increase_stat(xdp_stat, 1, &rx_ring->syncp);

        return verdict;
}
#endif /* ENA_XDP_H */